DALTON TRANSACTIONS
·
2021
·Vol. 50
·期 43
·15793-15801
·
IF 4.39
Meng Liu,Jichao Wang,Bibimaryam Mousavi,Hou Xiaotong,Nikom Klomkliang,Somboon Chaemchuen
The post-thermal treatment (PTT) method was applied for crystal transformation on the structure of zeolitic imidazolate frameworks (ZIFs) from 2D to 3D under solvent-free conditions. The investigation was performed based on bridging of the cobalt ions by the 2-methylimidazole linker to form the ZIF structure. Extensive characterization revealed that the reaction mechanism was a transformation in the solid crystal phase and resulted from the de-coordination of the framework and reformation of the crystalline structure. In addition, the PTT method opens the opportunity to simultaneously dope transition metals (Zn, Co, Fe, Ni, and Mn) in the framework during the transformation of ZIFs. The materials with doped metals showed enhanced properties and excellent performance for applications including gas adsorption, dye degradation, and the catalytic activity of CO2 fixation.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CARBON
·
2025
·
IF 11.6
Zi-cheng Tang,Yu-long Liu,Zi-jie Huang,Qin Wang,De-xiang Sun,Jing-hui Yang,Xiao-dong Qi,Yong Wang
Solid-liquid phase change materials (PCMs) suffer from liquid phase leakage, limited heat conductivity, and insufficient light absorption, which provide significant obstacles for solar energy storage. In this study, Zn–Co bimetallic ZIF structures with three morphologies were assembled on melamine foam (MF) by different synthesis conditions, followed by high-temperature carbonization to fabricate a hierarchical framework, in which ZIF-derived carbon layers integrated into carbonized melamine foam (CMF). Upon encapsulating energy storage unit paraffin wax (PW), the resultant CMF@Co–N/C/PW composite PCMs demonstrated superior encapsulation performance, enhanced thermal conductivity, excellent capacity for photothermal conversion and thermal storage. The hierarchical framework was comprised of ZIF-derived carbon nanostructures integrated with three-dimensional carbon skeleton, which provided a dual encapsulation effect and achieved a dimensional retention ratio of 95.71 %. Additionally, CMF@Co–N/C/PW exhibited a high phase change latent heat of 220.90 J/g and proved to be a reliable long-term thermal cycle system. Benefiting from the continuous carbon skeleton, CMF@Co–N/C/PW exhibited a noteworthy enhancement in thermal conductivity, showing a 100 % increase compared to pristine PW. More importantly, the impressive photothermal conversion efficiency of up to 93.65 % was attributed to the synergistic effects of Co nanoparticles, nitrogen-doped defective carbon, and multiple light scattering and absorption of the hierarchical network. The developed composite PCMs hold considerable promise in solar energy conversion applications.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Zhan Li,PingPing Yang,Shichen Yan,Qianrong Fang,Ming Xue,Shilun Qiu
An upsurge in searching membranes with high selectivity, permeability, and stability, which have been considered to be promising in the membrane-based gas separation process, has received huge attentions in academia and industry. In this work, we demonstrated a new molecular sieving ZIF membrane, which has a unique mixed-ligand ZIF structure constructed by two bulk imidazolate linkers within the zeolite GIS topology, resulting in appropriate aperture size, strong affinity to CO2, exceptional thermal and chemical stabilities, and superhydrophobic properties. Benefited from these features, the resulting JUC-160 membrane indeed exhibited remarkable separation efficiency and stability, with excellent H2/CO2 selectivity of 26.3 and considerable H2 permeance of 9.75 × 10–7 mol m–2 s–1 Pa–1 under high temperature up to 200 °C. Furthermore, owing to its superhydrophobicity, the JUC-160 membrane could maintain its prominent separation performance even with the presence of steam.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ACS Omega
·
2024
·
IF 3.7
Kaifei Mu,Jiang Wang,Meizhen Gao,Yanjun Wu,Qi Shi,Jinxiang Dong
Organic amides as solvents and structure directing agents (SDAs) are crucial for synthesizing zeolitic imidazolate frameworks (ZIFs). However, current research focuses only on the use of short alkyl-chain amides as solvents/SDAs. Here, we investigate the role of amides with varying alkyl-chain lengths on the structures and topologies of Zn(Im)2 polymorphs. Using short alkyl-chain amides as solvents, the Zn(Im)2 topological structures are affected by the synthesis conditions, leading to “one SDA/multiple topological structures”. In contrast, when long alkyl-chain amides are used as solvents, the Zn(Im)2 topological structures are essentially unaffected by other synthesis conditions. Thus, long alkyl-chain amides are shown for the first time to exhibit a significant template role, leading to “one template/one topological structure”. Specifically, the use of long alkyl-chain N,N-dimethyl-Cn amides (abbreviated as DM-Cn amides, n = 3, 4, 6, 8, and 10) can lead to only DTF-type Zn(Im)2 frameworks under broad crystallization conditions. Single-crystal X-ray diffraction confirmed that the exquisite structural compatibility between long alkyl-chain DM-Cn amides and the DFT-type Zn(Im)2 framework results in a highly regular head-to-tail arrangement of amides along the (kaa-lov)n chain of the DFT framework. The template role for long alkyl-chain amides was further identified to be multiple C–H···π interactions between DM-Cn amides and Zn(Im)2 frameworks thanks to molecular simulations.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）